The outbreak of coronavirus disease 2019 (COVID-19), which began in December 2019, is still ongoing in Korea, with >9,000 confirmed cases as of March 25, 2020. COVID-19 is a severe acute respiratory ...syndrome Coronavirus 2 (SARS-CoV-2) infection, and real-time reverse transcription-PCR is currently the most reliable diagnostic method for COVID-19 around the world. Korean Society for Laboratory Medicine and the Korea Centers for Disease Prevention and Control propose guidelines for diagnosing COVID-19 in clinical laboratories in Korea. These guidelines are based on other related domestic and international guidelines, as well as expert opinions and include the selection of test subjects, selection of specimens, diagnostic methods, interpretation of test results, and biosafety.
The pandemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused a public health emergency, and research on the development of various types of vaccines is rapidly progressing ...at an unprecedented development speed internationally. Some vaccines have already been approved for emergency use and are being supplied to people around the world, but there are still many ongoing efforts to create new vaccines. Virus-like particles (VLPs) enable the construction of promising platforms in the field of vaccine development. Here, we demonstrate that non-infectious SARS-CoV-2 VLPs can be successfully assembled by co-expressing three important viral proteins membrane (M), envelop (E) and nucleocapsid (N) in plants. Plant-derived VLPs were purified by sedimentation through a sucrose cushion. The shape and size of plant-derived VLPs are similar to native SARS-CoV-2 VLPs without spike. Although the assembled VLPs do not have S protein spikes, they could be developed as formulations that can improve the immunogenicity of vaccines including S antigens, and further could be used as platforms that can carry S antigens of concern for various mutations.
Obesity can be caused by microbes producing metabolites; it is thus important to determine the correlation between gut microbes and metabolites. This study aimed to identify gut ...microbiota-metabolomic signatures that change with a high-fat diet and understand the underlying mechanisms. To investigate the profiles of the gut microbiota and metabolites that changed after a 60% fat diet for 8 weeks, 16S rRNA gene amplicon sequencing and gas chromatography-mass spectrometry (GC-MS)-based metabolomic analyses were performed. Mice belonging to the HFD group showed a significant decrease in the relative abundance of Bacteroidetes but an increase in the relative abundance of Firmicutes compared to the control group. The relative abundance of Firmicutes, such as Lactococcus, Blautia, Lachnoclostridium, Oscillibacter, Ruminiclostridium, Harryflintia, Lactobacillus, Oscillospira, and Erysipelatoclostridium, was significantly higher in the HFD group than in the control group. The increased relative abundance of Firmicutes in the HFD group was positively correlated with fecal ribose, hypoxanthine, fructose, glycolic acid, ornithine, serum inositol, tyrosine, and glycine. Metabolic pathways affected by a high fat diet on serum were involved in aminoacyl-tRNA biosynthesis, glycine, serine and threonine metabolism, cysteine and methionine metabolism, glyoxylate and dicarboxylate metabolism, and phenylalanine, tyrosine, and trypto-phan biosynthesis. This study provides insight into the dysbiosis of gut microbiota and metabolites altered by HFD and may help to understand the mechanisms underlying obesity mediated by gut microbiota.
Accumulating evidence shows that atrial fibrillation (AF) is associated with an increased risk of dementia. Catheter ablation for AF prolongs the duration of sinus rhythm, thereby improving the ...quality of life. We investigated the association of catheter ablation for AF with the occurrence of dementia.
Using the Korean National Health Insurance Service database, among 194 928 adults with AF treated with ablation or medical therapy (antiarrhythmic or rate control drugs) between 1 January 2005 and 31 December 2015, we studied 9119 patients undergoing ablation and 17 978 patients managed with medical therapy. The time-at-risk was counted from the first medical therapy, and ablation was analysed as a time-varying exposure. Propensity score-matching was used to correct for differences between the groups. During a median follow-up of 52 months, compared with patients with medical therapy, ablated patients showed lower incidence and risk of overall dementia (8.1 and 5.6 per 1000 person-years, respectively; hazard ratio 0.73, 95% confidence interval 0.58-0.93). The associations between ablation and dementia risk were consistently observed after additionally censoring for incident stroke (hazard ratio 0.76, 95% confidence interval 0.61-0.95) and more pronounced in cases of ablation success whereas no significant differences observed in cases of ablation failure. Ablation was associated with lower risks of dementia subtypes including Alzheimer's disease and vascular dementia.
In this nationwide cohort of AF patients treated with catheter ablation or medical therapy, ablation was associated with decreased dementia risk. This relationship was evident after censoring for stroke and adjusting for clinical confounders.
External quality assessment (EQA) is essential for ensuring reliable test results, especially when laboratories are using assays authorized for emergency use for newly emerging pathogens. We ...developed an EQA panel to assess the quality of real-time reverse transcription PCR assays being used in South Korea to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the participation of 23 public health organization laboratories and 95 nongovernmental laboratories involved in SARS-CoV-2 testing, we conducted qualitative and semiquantitative performance assessments by using pooled respiratory samples containing different viral loads of SARS-CoV-2 or human coronavirus OC43. A total of 110 (93.2%) laboratories reported correct results for all qualitative tests; 29 (24.6%) laboratories had >1 outliers according to cycle threshold values. Our EQA panel identified the potential weaknesses of currently available commercial reagent kits. The methodology we used can provide practical experience for those planning to conduct evaluations for testing of SARS-CoV-2 and other emerging pathogens in the future.
Temporal changes in the healthcare burden of atrial fibrillation (AF) are less well known in rapidly ageing Asian countries. We examined trends in hospitalisations, costs, treatment patterns and ...outcomes related to AF in Korea.
Using the National Health Insurance Service (NHIS) database involving the entire adult Korean population (n=41 701 269 in 2015), we analysed a nationwide AF cohort representing 931 138 patients with AF. We studied all hospitalisations due to AF from 2006 to 2015.
Overall, hospitalisations for AF increased by 420% from 767 to 3986 per 1 million Korean population from 2006 to 2015. Most admissions occurred in patients aged ≥70 years, and the most frequent coexisting conditions were hypertension, heart failure and chronic obstructive pulmonary disease. Hospitalisations mainly due to major bleeding and AF control increased, whereas hospitalisations mainly due to ischaemic stroke and myocardial infarction decreased. The total cost of care increased even after adjustment for inflation from €68.4 million in 2006 to €388.4 million in 2015, equivalent to 0.78% of the Korean NHIS total expenditure. Overall in-hospital mortality decreased from 7.5% in 2006 to 4.3% in 2015. The in-hospital mortality was highest in patients ≥80 years of age (7.7%) and in patients with chronic kidney disease (7.4%).
AF hospitalisations have increased exponentially over the past 10 years in Korea, in association with an increase in comorbid chronic diseases. Mortality associated with AF hospitalisations decreased during the last decade, but hospitalisation costs have markedly increased.
Most data on the clinical epidemiology of atrial fibrillation (AF) are reported from Western populations, and data for Asians are limited. We aimed to investigate the 10-year trends of the prevalence ...and incidence of non-valvular AF and provide prevalence projections till 2060 in Korea. We also investigated the annual risks of adverse outcomes among patients with AF.
Using the Korean National Health Insurance Service database involving the entire Korean population, a total of 679,416 adults with newly diagnosed AF were identified from 2006 to 2015. The incidence and prevalence of AF and risk of adverse outcomes following AF onset were assessed.
The prevalence of AF progressively increased by 2.10-fold from 0.73% in 2006 to 1.53% in 2015. The trend of its incidence was flat with a 10-year overall incidence of 1.77 per 1,000 person-years. The prevalence of AF is expected to reach 5.81% (2,290,591 patients with AF) in 2060. For a decade, the risk of all-cause mortality following AF declined by 30% (adjusted hazard ratio HR: 0.70, 95% confidence interval CI: 0.68–0.72), heart failure by 52% (adjusted HR: 0.48, 95% CI: 0.44–0.51), and ischemic stroke by 9% (adjusted HR: 0.91, 95% CI: 0.88–0.93).
The burden of AF among Asian patients is increasing. Although the overall risks of cardiovascular events and death following AF onset have decreased over a decade, the event rates are still high. Optimized management of any associated comorbidities should be part of the holistic management approach for patients with AF.
The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for High Blood Pressure in Adults redefined hypertension as systolic blood pressure (BP) ≥130 mm Hg or diastolic ...BP ≥80 mm Hg. The optimal BP for patients with atrial fibrillation (AF) is uncertain.
The goal of this study was to investigate the impacts of the 2017 ACC/AHA guideline and to determine the ideal BP threshold for the management of high BP in patients with AF.
This study analyzed data for 298,374 Korean adults with oral anticoagulant–naive, nonvalvular AF obtained from the National Health Insurance Service database from 2005 to 2015.
According to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure guideline, 62.2% of the individuals in our sample had hypertension. After applying the 2017 ACC/AHA guideline, 79.4% had hypertension, including 17.2% with newly redefined hypertension (130 to 139/80 to 89 mm Hg). Those with newly redefined hypertension had greater risks of major cardiovascular events (hazard ratio: 1.07; 95% confidence interval: 1.04 to 1.10; p < 0.001), ischemic stroke, intracranial hemorrhage, and heart failure admission, compared with nonhypertensive patients (<130/80 mm Hg). Among patients with AF undergoing hypertension treatment, patients with BP ≥130/80 mm Hg or <120/80 mm Hg were at significantly higher risks of major cardiovascular events than patients with BP of 120 to 129/<80 mm Hg.
Patients with AF and newly redefined hypertension according to the 2017 ACC/AHA guideline were at higher risk of major cardiovascular events, suggesting that the new BP threshold is beneficial for timely diagnosis and intervention. BP of 120 to 129/<80 mm Hg was the optimal BP treatment target for patients with AF undergoing hypertension treatment.
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Background Dose adjustment of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in some patients with atrial fibrillation (AF), based on selected patient factors or concomitant ...medications. We assessed the frequency of label adherence of NOAC dosing among AF patients and the associations between off-label NOAC dosing and clinical outcomes. Methods and Results We evaluated 53 649 AF patients treated with an NOAC using Korean National Health Insurance Service database during the period from 2013 to 2016. NOAC doses were classified as either underdosed or overdosed, consistent with Korea Food and Drug Administration labeling. Cox proportional hazards regression was performed to investigate the effectiveness and safety outcomes including stroke or systemic embolism, major bleeding, and all-cause mortality. Overall, 16 757 NOAC-treated patients (31.2%) were underdosed, 4492 were overdosed (8.4%), and 32 400 (60.4%) were dosed appropriately according to drug labeling. Compared with patients with label adherence, those who were underdosed or overdosed were older (aged 71±8 and 75±7 years versus 70±9 years, respectively;
<0.001) and had higher CHA
DS
-VASc scores (4.6±1.7 and 5.3±1.7 versus 4.5±1.8, respectively;
<0.001). NOAC overdosing was associated with increased risk for stroke or systemic embolism (5.76 versus 4.03 events/100 patient-years,
<0.001), major bleeding (4.77 versus 2.94 events/100 patient-years,
<0.001), and all-cause mortality (5.43 versus 3.05 events/100 patient-years,
<0.001) compared with label-adherent use. Conclusions In real-world practice, a significant proportion (almost 2 in 5) of AF patients received NOAC doses inconsistent with drug labeling. NOAC overdosing is associated with worse clinical outcomes in Asian AF patients.
Background
Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes ...and those without HCM at AF catheter ablation (AFCA) and analyzed post‐AFCA reverse remodeling and AF recurrence based on HCM presence and subtype.
Methods
Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age‐, gender‐, and AF type‐matched. Between AF‐HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1‐year follow‐up, and procedural outcomes over the course of follow‐up between two groups.
Results
A total of 122 AF‐HCM patients and 318 control patients were included. AF‐HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p < .001). However, LAWT did not differ from control group. A year after AFCA, degree of LA reverse remodeling was significantly lower in AF‐HCM than in control group (ΔLA dimension, p = .025). Nonapical HCM (HR 1.71; 95% CI 1.05–2.80), persistent AF (HR 1.46; 95% CI 1.05–2.04), and LA dimension (HR 1.04; 95% CI 1.01–1.06) were independent risk factors for AF recurrence. During 78.0 months of follow‐up, nonapical HCM patients showed higher AF recurrence rate than both apical HCM (log‐rank p = .005) and control patients (log‐rank p = .002).
Conclusions
The presence of HCM, particularly nonapical HCM, displayed increased LA hemodynamic loading with diastolic dysfunction and had poorer rhythm outcomes after AFCA compared to both apical HCM and control group.
Comparison of LA hemodynamic and structural parameters between AF‐HCM and control groups and the difference of LA reservoir strain according to the type of HCM with rhythm outcome after AFCA in three groups.
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